The present invention concerns a process for the recognition of an aerial target from its radar echo.
The present invention is applied in particular to the recognition of aerial targets from an airborne radar, for example when a pilot of a fighter aircraft wishes to know, before visual contact is established, the nature of the target (e.g. jet airliner, propellor aircraft, military aircraft, etc.) and, if possible, not only the general category of target, but also, for a given category, the precise type or model (for example, for an airliner-type aircraft, whether it is an Airbus, a DC-10, etc.).
The present invention is not, however, restricted to this application for the recognition of targets from an airborne radar; it can also be applied for example to the recognition of targets by land-based or naval radar, provided this radar allows, as will be seen later, acquisition in Doppler mode.
Until the present time, when an aircraft enters air space covered by a radar, the only means of obtaining precise identification is by radio or by an IFF (Identification Friend or Foe) identification signal, if the aircraft in question is cooperative.
On the other hand, if the target does not respond to radio interrogation or IFF and if it is out of visual range, there is no means of determining whether or not it is hostile, or even whether it is really an aircraft or an electronic countermeasure intended as a lure, to jam the radar.
Only visual identification may then be used, which requires good visibility and implies greatly reduced identification distance and late identification.